The present invention relates to a spraying apparatus and especially to a multipurpose spraying, dispensing or mixing apparatus having a nozzle member.
Liquid aspirators are commonly employed to apply diluted solutions containing chemicals such as pesticides, fungicides, herbicides, and fertilizers to lawns or garden foliage. Such aspirators are also commonly used to dispense detergents (including liquid, gelatinous and dry detergents). There are two general types of sprayers that are employed for these functions, those that use concentrated liquid chemical solutions of various viscosities, and those that utilize gelatinous substances or powdered dry chemicals. Typically, both types of sprayers are attached to a garden hose.
In the case of the liquid chemical aspiration sprayer, the pressure of the water delivered by the hose through the sprayer creates a negative pressure gradient or venturi that causes the chemical solution to be aspirated into the water stream, thereby providing a diluted solution to be sprayed.
U.S. Pat. No. 4,901,923, for example, discloses a variable dilution ratio hose-end aspirator sprayer. The sprayer comprises a container for housing the liquid to be mixed with the water and a mixing head having a nozzle at one end thereof and a garden hose attachment device at the other end thereof. The sprayer also includes a mixing chamber within the mixing head, a hose for communicating the liquid from the container to the mixing head and a disk having a plurality of apertures therein rotatably mounted in the mixing head to control flow from the container to the mixing chamber. A flow tube communicates liquid in the container to the inlet in the mixing chamber through a selected aperture in the disk so that the liquid is diluted with pressurized water at a dilution ratio determined by the size of the aperture aligned with the tube and the mixing chamber. The sprayer also includes a cleaning orifice positioned circumferential from the mixing chamber so that each aperture of the disk may be selectively aligned with the cleaning orifice for cleaning.
U.S. Pat. No. 5,039,016 also discloses an aspiration-type chemical sprayer for dispensing small quantities of a liquid-based chemical into a stream of carrier fluid. The sprayer includes a sprayer head assembly sealingly mounted onto a container for storing the chemical to be disbursed. The sprayer head assembly also includes a multifunction unitary valve for providing a range of aspiration rates simultaneously with full communication of the container interior to atmospheric pressure. The valve may also include means for positive and simultaneous closure of the aspiration and vent passages so as to seal the chemical in the container when the sprayer is not in use.
U.S. Pat. No. 5,100,059 similarly discloses an aspiration-type chemical sprayer including a sprayer head assembly sealingly mounted onto a container holding chemicals such as pesticides or fertilizers. A unitary valve in the sprayer head assembly controls carrier fluid flow from a pressurized source of water while simultaneously providing a controlled aspiration rate and full communication of the container interior to atmospheric pressure. The valve additionally includes simultaneous closure of the carrier fluid, aspiration and vent passage ways so as to seal the chemical in the container when the sprayer is not being used.
In general, the liquid chemical aspiration sprayers include a container for holding the chemical solution to be diluted and sprayed and a sprayer/mixing head. The base portion of the sprayer head serves as a cover for the chemical container. Such sprayer heads generally include an adapter for connecting the sprayer head to a standard garden hose, and a hand valve for turning on and off the flow of water from the garden hose. The sprayer head also includes an aperture over which water from the garden hose passes to mix with undiluted chemical solution from the container. Such sprayer heads may also include a venturi chamber in which the water from the garden hose mixes with the chemical from the container.
In principle, as water passes over the aperture or through the venturi chamber, a siphoning or vacuum action is created by virtue of the velocity of the water passing over the aperture or through the chamber, to draw chemical from the container into the water stream for dilution. The basis of operation of these sprayers is, in closed venturi type systems, Bernoulli""s principle. And, in aspiration type sprayers open to the atmosphere, the principle under which product is drawn from the container is known as the Kuanda effect.
Liquid chemical aspiration sprayers are of two general types. Many of these sprayers have a fixed, nonadjustable dilution ratio. However, other commercially available liquid chemical aspiration sprayers provide for multiple dilution ratios. These multiple dilution ratio sprayers generally do not require chemical premixing and directly provide the desired concentration of liquid chemical into the carrier stream. The variation in the dilution ratios is generally provided in these sprayers by either varying the size of the opening of the passageway between the chemical container to the mixing chamber, or by varying the size of the vent opening which allows air into the mixing chamber in order to control the level of vacuum and the resulting siphoning action on the liquid chemical from the container. In both types of multiple dilution sprayers, a rotatable wheel or slideable stem, which incorporates orifices of various sizes, is interposed in the passageway or the vent opening and is used to select the appropriate dilution ratio.
Sprayers that are to be used for wettable chemical powders also utilize the same basic container sprayer/mixing head design as liquid chemical aspiration sprayers. But, when the water delivered from the hose enters the sprayer/mixing head, a portion of that stream is directed into the container to dissolve and dilute the wettable chemical powder therein. Once diluted, the product solution enters that portion of the water stream exiting the sprayer under the influence of the negative pressure gradient described above and by displacement of the solution within the container by incoming water.
U.S. Pat. No. 5,007,588 also discloses an aspiration-type sprayer comprising a sprayer head which is permanently attachable to a container in which additive material is received. The sprayer head may be moveable between positions controlling the degree of aspiration affected, and is provided with a cap moveable between a first position in which the cap seals the container and prevents the additive material from escaping therefrom and a second position in which the container is unsealed and aspiration of the contents thereof can take place. Elements may be provided as part of the sprayer assembly for controlling the flow of the aspirating fluid. The cap is secured in its sealing position by an element which requires special manipulating for release, thereby providing an important safety feature.
U.S. Pat. Nos. 5,320,288 and 5,372,310 each disclose an aspiration-type sprayer that is attached to a product container. This sprayer includes a control mechanism for simultaneously controlling the flow of the carrier stream through the nozzle and the chemical product. This sprayer provides the ability to spray both the chemical solution and pure carrier fluid, as well as the ability to be placed in a sealed xe2x80x9coffxe2x80x9d position. More particularly, the means for controlling the flow of carrier fluid can be opened while the chemical product is sealed within the container. In this sprayer, the product channel is both substantially linear and substantially reduced in length.
U.S. Pat. Nos. 5,320,288 and 5,372,310 also disclose a means to dispense a soluble solid chemical or a wettable powder. The control mechanism can be slid into a position where a portion of the carrier stream is diverted into the container to dilute the dry chemical. The resulting chemical solution then exits the container via a product channel and is placed back into the non-diverted portion of the carrier stream, again under the influence of the aforementioned negative pressure gradient and displacement with incoming water.
Typically, in the above-described sprayers, including the apparatus described in U.S. Pat. Nos. 5,230,288 and 5,372,310, product flows through one or more apertures in the valve or apparatus body and/or selection element. The selection element may be connectively engaged to the valve body. The connection between the selection element and the valve body must be airtight in order to provide a vacuum necessary for aspiration. In order to provide the airtight seal, a separate sealing means is generally provided in the form of a gasket, membrane or o-rings.
A need has been recognized in connection with the provision of a spraying apparatus, and a control arrangement therefor, that lends itself to durability and operational efficiency.
Various objects and advantages of the present invention will become apparent as the following description of the presently preferred embodiments and presently preferred methods of practicing the invention proceeds.